The present invention relates generally to computer data storage backup, and more particularly, to remote control of a secondary storage subsystem through a primary storage subsystem.
Due to advances in computer technology, there has been an ever-increasing need for data storage in data processing networks. In a typical data processing network, there has been an increase in the number of volumes of data storage and an increase in the number of hosts needing access to the volumes. This has been especially true for networks of workstations. Not only have a greater number of workstations been added to the typical network, but also the increase in data processing capabilities of a typical workstation has required more data storage per workstation for enhanced graphics and video applications.
Fortunately for computer users, the cost of data storage has continued to decrease at a rate approximating the increase in need for storage. For example, economical and reliable data storage in a data network can be provided by a storage subsystem including a Redundant Array of Independent Disks (RAID). Presently it is practical to provide a single data storage subsystem with up to 20 terabytes (TB) of storage, or approximately 4000 logical volumes, using magnetic disk drives each having a storage capacity of 46 gigabytes.
Unfortunately for network administrators, the development of services for storage management has lagged behind the increase in storage to be managed. Consequently, the cost of storage management has become relatively more significant. More troubling is the difficulty of maintaining the same level of management service as the amount of storage increases. For example, users are accustomed to being provided with backup and restore services for their data that is stored on the network. Users are encouraged to store their data on the network so that it can be shared by other authorized users and maintained in a cost-effective manner in accordance with corporate document retention policies. However, data stored on the network is always subject to some chance of loss due to a severe failure of the data storage system. Backup and restore services are a conventional way of reducing the impact of data loss from the network storage. To be effective, however, the data should be backed up frequently, and the data should be restored rapidly from backup after the storage system failure. As the amount of storage on the network increases, it is more difficult to maintain the frequency of the data backups, and to restore the data rapidly after a storage system failure.
In accordance with one aspect of the invention, there is provided a method of operating a data storage system including a primary data storage subsystem and a secondary data storage subsystem linked to the primary data storage subsystem for transfer of backup data between the primary data storage subsystem and the secondary data storage subsystem. The secondary data storage subsystem includes a tape library unit for storage of the backup data. The method includes the primary data storage subsystem receiving from a host processor a backup media remote control request, the primary data storage subsystem sending to the secondary data storage subsystem a backup media remote control command corresponding to the backup media remote control request, the secondary data storage subsystem receiving the backup media remote control command, and the tape library unit executing the backup media remote control command.
In accordance with another aspect, the invention provides a method of operating a data storage system including a primary data storage subsystem and a secondary data storage subsystem linked to the primary data storage subsystem for transfer of backup data between the primary data storage subsystem and the secondary data storage subsystem. The secondary data storage subsystem includes a tape library unit for storage of the backup data. The method includes the primary data storage subsystem receiving from a first host processor a backup media remote control request, the primary data storage subsystem sending to the secondary data storage subsystem a backup media remote control command corresponding to the backup media remote control request, the secondary data storage subsystem receiving the backup media remote control command, tape library unit executing the backup media remote control command and returning an acknowledgment to the primary data storage subsystem, and the primary data storage subsystem returning the acknowledgment to the first host processor. The method further includes the primary data storage subsystem receiving from a second host processor a backup request for backup of specified data in the primary data storage, and in response the primary data storage subsystem transmitting at least one command to the secondary data storage subsystem for storing a backup version of the specified data in tape storage in the tape library unit without requiring the second host processor to issue backup media remote control requests.
In accordance with another aspect, the invention provides a data storage system including a primary data storage subsystem and a secondary data storage subsystem. The primary data storage subsystem includes primary data storage and a storage controller coupled to the primary data storage for controlling access to the primary data storage. The storage controller has at least one data port for coupling to at least one host processor for receiving data access commands from the host processor for access to the primary data storage. The secondary data storage subsystem is linked to the storage controller of the primary data storage subsystem for transfer of backup data between the primary data storage subsystem and the secondary data storage subsystem. The secondary data storage subsystem includes a tape library unit for storage of the backup data. The storage controller of the primary data storage subsystem is programmed for receiving from the host processor a backup media remote control request, and sending to the secondary data storage subsystem a backup media remote control command corresponding to the backup media remote control request for execution of the backup media remote control command by the tape library unit.
In accordance with yet another aspect, the invention provides a data storage system including a primary data storage subsystem and a secondary data storage subsystem. The primary data storage subsystem includes primary data storage, a primary directory to information stored in the primary data storage, and a storage controller coupled to the primary data storage and the primary directory for controlling access to the primary data storage. The storage controller has at least one data port for coupling to a plurality of host processors for receiving data access commands from the host processors for access to the primary data storage. The secondary data storage subsystem is linked to the storage controller of the primary data storage subsystem for transfer of backup data between the primary data storage subsystem and the secondary data storage subsystem. The secondary data storage subsystem includes a tape library unit for storage of the backup data, a secondary directory to tapes in the tape library unit and backup versions stored on the tapes in the tape library unit, and a processor linking the secondary directory and the tape library unit for control of access to the tapes in the tape library unit. The storage controller of the primary data storage subsystem is programmed for receiving from the host processors backup media remote control requests, and sending to the secondary data storage subsystem backup media remote control commands corresponding to the backup media remote control requests for execution of the backup media remote control commands by the tape library unit, and for returning acknowledgments of the backup media remote control commands from the secondary data storage subsystem to the host processors. The storage controller of the primary data storage subsystem is further programmed for receiving from the host processors backup requests for backup of specified data in the primary data storage, and in response for transmitting commands to the secondary data storage subsystem for storing backup versions of the specified data in tape storage in the tape library unit without requiring the host processors to issue backup media remote control requests for storing the backup versions of the specified data in the tape storage of the tape library unit.
In accordance with a final aspect, the invention provides a machine readable program storage device containing a program executable by a storage controller of a data storage subsystem having primary data storage. The storage controller has at least one data port for receiving storage access requests from at least one host processor. The storage controller is linked to a tape library unit for transfer of backup data between the storage controller and the tape library unit. The program is executable by the storage controller for receiving from the host processors storage access requests and in response controlling access of the host processors to the primary data storage. The program is also executable by the storage controller for receiving from the host processors backup media remote control requests, and sending to the tape library unit backup media remote control commands corresponding to the backup media remote control requests for execution of the backup media remote control commands by the tape library unit, and for returning acknowledgments of the backup media remote control commands from the tape library unit to the host processors. The program is further executable by the storage controller for receiving from the host processors backup requests for backup of specified data in the primary data storage, and in response for transmitting commands to the tape library unit for storing backup versions of the specified data in tape storage in the tape library unit without requiring the host processors to issue backup media remote control requests for storing the backup versions of the specified data in tape storage of the tape library unit.